Study On Formation Stability And The Stress Mechanism Of Supporting Structure In Subway Engineering By Double-shield TBM Construction

TBM construction method in deeply buried long tunnels has great advantages.There are less engineering project that can be referenced in subway engineering.Because the weak ground adaptability of TBM and the complexity and importance of the subway engineering.To avoid the damage to the building on the ground,the Surrounding rock disturbance range should be controlled in construction.So,aimed construction characteristics of TBM in subway engineering.through data survey,theoretical analysis,numerical simulation method,research on the influence of tunneling parameters on surrounding rock stability and the interaction mechanism of different supporting methods and surrounding rock.The main contents and conclusions are as follows:(1)Combined with the actual situation of the project,the influence of different tunneling parameters on surrounding rock stability was analyzed by numerical simulation method under the condition of the intermediary weathered granite and strong weathered granite.The loose circle of surrounding rock under different tunneling parameters could be gained by minimum safety factor method,and the results are consistent with the field test results.(2)The interaction between three support method and surrounding rock were analyzed by numerical simulation method.The reasonable support method was gained for different surrounding rock conditions.The shotcrete-bolt support could meet the requirement under the condition of intermediary weathered granite.(3)The yielding approach index of surrounding rock could be gained by the data gained by numerical simulation under different surrounding rock conditions and different support methods.The results showed that shotcrete-bolt support and formworking concrete lining can better ensure the stability of surrounding rock under the condition of strong weathered granite.(4)studied on the construction method through special formation and section in subway engineering,the construction method that TBM through the fault zone and the existing building was put forward finally.